<!DOCTYPE html>
<html>
 
<head>
 <meta charset="utf-8">
 <title>猜数字游戏</title>
 <style>
  html {
   font-family: sans-serif;
  }
 
  body {
   width: 50%;
   max-width: 800px;
   min-width: 480px;
   margin: 0 auto;
  }
 
  .lastResult {
   color: white;
   padding: 3px;
  }
 </style>
</head>
 
<body>
 <h1>猜数字游戏</h1>
 
 <p>我刚才随机选定了一个100以内的自然数。看你能否在 10 次以内猜中它。每次我都会告诉你所猜的结果是高了还是低了。</p>
 
 <div class="form">
  <label for="guessField">请猜数: </label>
  <input type="text" id="guessField" class="guessField">
  <input type="submit" value="确定" class="guessSubmit">
 </div>
 
 <div class="resultParas">
  <p class="guesses"></p>
  <p class="lastResult"></p>
  <p class="lowOrHi"></p>
 </div>
 
 <script>
 
  let randomNumber = Math.floor(Math.random() * 100) + 1;
 
  const guesses = document.querySelector('.guesses');
  const lastResult = document.querySelector('.lastResult');
  const lowOrHi = document.querySelector('.lowOrHi');
 
  const guessSubmit = document.querySelector('.guessSubmit');
  const guessField = document.querySelector('.guessField');
 
  let guessCount = 1;
  let resetButton;
 
  function checkGuess() {
   let userGuess = Number(guessField.value);
   if (guessCount === 1) {
    guesses.textContent = '上次猜的数：';
   }
   guesses.textContent += userGuess + ' ';
 
   if (userGuess === randomNumber) {
    lastResult.textContent = '恭喜你！猜对了';
    lastResult.style.backgroundColor = 'green';
    lowOrHi.textContent = '';
    setGameOver();
   } else if (guessCount === 10) {
    lastResult.textContent = '!!!GAME OVER!!!';
    setGameOver();
   } else {
    lastResult.textContent = '你猜错了！';
    lastResult.style.backgroundColor = 'red';
    if (userGuess < randomNumber) {
     lowOrHi.textContent = '你猜低了！';
    } else if (userGuess > randomNumber) {
     lowOrHi.textContent = '你猜高了';
    }
   }
 
   guessCount++;
   guessField.value = '';
   guessField.focus();
  }
 
  guessSubmit.addEventListener('click', checkGuess);
 
  function setGameOver() {
   guessField.disabled = true;
   guessSubmit.disabled = true;
   resetButton = document.createElement('button');
   resetButton.textContent = '开始新游戏';
   document.body.appendChild(resetButton);
   resetButton.addEventListener('click', resetGame);
  }
 
  function resetGame() {
   guessCount = 1;
 
   const resetParas = document.querySelectorAll('.resultParas p');
   for (let i = 0; i < resetParas.length; i++) {
    resetParas[i].textContent = '';
   }
 
   resetButton.parentNode.removeChild(resetButton);
 
   guessField.disabled = false;
   guessSubmit.disabled = false;
   guessField.value = '';
   guessField.focus();
 
   lastResult.style.backgroundColor = 'white';
 
   randomNumber = Math.floor(Math.random() * 100) + 1;
  }
 
 </script>
</body>
</html>